scholarly journals Leader-Following Consensus and Formation Control of VTOL-UAVs with Event-Triggered Communications

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5498 ◽  
Author(s):  
J. Fermi Guerrero-Castellanos ◽  
Argel Vega-Alonzo ◽  
Sylvain Durand ◽  
Nicolas Marchand ◽  
Victor R. Gonzalez-Diaz ◽  
...  
Keyword(s):  
Control Strategy ◽  
Formation Control ◽  
Control Law ◽  
Loop Control ◽  
Control Approach ◽  
Communication Topology ◽  
Leader Following ◽  
Error Space ◽  
Virtual Leader ◽  
Event Triggered

This article presents the design and implementation of an event-triggered control approach, applied to the leader-following consensus and formation of a group of autonomous micro-aircraft with capabilities of vertical take-off and landing (VTOL-UAVs). The control strategy is based on an inner–outer loop control approach. The inner control law stabilizes the attitude and position of one agent, whereas the outer control follows a virtual leader to achieve position consensus cooperatively through an event-triggered policy. The communication topology uses undirected and connected graphs. With such an event-triggered control, the closed-loop trajectories converge to a compact sphere, centered in the origin of the error space. Furthermore, the minimal inter-sampling time is proven to be below bounded avoiding the Zeno behavior. The formation problem addresses the group of agents to fly in a given shape configuration. The simulation and experimental results highlight the performance of the proposed control strategy.

scholarly journals FORMATION CONTROL OF MULTIPLE UNICYCLE-TYPE ROBOTS USING LIE GROUP

2016 ◽  
Vol 56 (1) ◽  
pp. 1
Author(s):  
Youwei Dong ◽  
Ahmed Rahmani
Keyword(s):  
Group Theory ◽  
Numerical Simulations ◽  
Lie Group ◽  
Formation Control ◽  
Directed Acyclic Graph ◽  
Control Law ◽  
Lie Group Theory ◽  
Acyclic Graph ◽  
Communication Topology

In this paper the formation control of a multi-robots system is investigated. The proposed control law, based on Lie group theory, is applied to control the formation of a group of unicycle-type robots. The communication topology is supposed to be a rooted directed acyclic graph and fixed. Some numerical simulations using Matlab are made to validate our results.

The Null Space Based Cooperative Formation Control for UAVs Swarm

2013 ◽  
Vol 341-342 ◽  
pp. 824-829
Author(s):  
Shi You Dong ◽  
Xiao Ping Zhu ◽  
Guo Qing Long
Keyword(s):  
Control Strategy ◽  
Formation Control ◽  
Local Minimum ◽  
Null Space ◽  
Potential Functions ◽  
Good Effect ◽  
Artificial Potential Field ◽  
Minimum Problem ◽  
Control Approach ◽  
Local Minimum Problem

In this paper, the formation problem of UAVs swarm is studied based on a combination of the potential functions. On the basis of mathematical models of the traditional artificial potential field,a new formation potential function is proposed. The potential functions is merged using null space control strategy which is capable of dealing with conflicts among elementary potential functions and avoid local minimum problem. The results achieved by computer simulations suggest that the control approach can produces good effect.

Control of a Digital Micromirror Device Using Input Shaping

2007 ◽  
Author(s):  
H. Jammoussi ◽  
S. Choura ◽  
E. M. Abdel-Rahman ◽  
H. Arafat ◽  
A. Nayfeh ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Control Strategy ◽  
Nonlinear Function ◽  
Input Voltage ◽  
Open Loop ◽  
Input Shaping ◽  
Control Law ◽  
Digital Micromirror Device ◽  
Open Loop Control ◽  
Loop Control

In this paper, an open-loop control strategy is proposed for maneuvering the angular motion of a Digital Micromirror Device (DMD). The control law is based on a micromirror model that accounts for both bending and torsion motions. The model characterizes two DMD configurations: with and without contact with the substrate. The device is actuated using an electrostatic field which is a nonlinear function of the states and input voltage. The proposed control strategy is a Zero Vibration (ZV) shaper. It overshoots the DMD to its desired final angle by appropriately varying two independent input voltages. Actuating voltages and switching times are determined to maneuver the DMD from −10° to +10° tilt angles while reducing the residual vibrations.

Optimal formation control with limited communication for multi-unmanned aerial vehicle in an obstacle-laden environment

2016 ◽  
Vol 231 (6) ◽  
pp. 979-997 ◽  
Author(s):  
Xiao Lin Ai ◽  
Jian Qiao Yu ◽  
Yong Bo Chen ◽  
Fang Zheng Chen ◽  
Yuan Chuan Shen
Keyword(s):  
Optimal Control ◽  
Control Problem ◽  
Formation Control ◽  
Control Laws ◽  
Control Approach ◽  
Practical Applications ◽  
Limited Communication ◽  
Aerial Vehicle ◽  
The Stability ◽  
Virtual Leader

This paper investigates the formation control problem of multiple unmanned aerial vehicles (UAVs) with limited communication in a known and realistic obstacle-laden environment. In order to deal with the limited communication constraints, the leader–follower strategy and the virtual leader strategy are integrated into an optimal control framework to formulate this formation control problem. This combination formation framework can be achieved by integrating a redefined directed graph and a proposed information vector. In more practical applications, an obstacle/collision avoidance strategy is achieved by constructing a non-quadratic cost function innovatively using a virtual flow field approach. The proposed optimal control laws, which derive from the local information rather than the global information, are proved to guarantee the stability of the close-loop system by an inverse optimal control approach. The simulation results demonstrate the effectiveness of the formation flight of multiple UAVs with limited communication in an obstacle-laden environment.

scholarly journals Flocking of Multi-Agent System with Nonlinear Dynamics via Distributed Event-Triggered Control

2019 ◽  
Vol 9 (7) ◽  
pp. 1336 ◽  
Author(s):  
Yanhua Shen ◽  
Zhengmin Kong ◽  
Li Ding
Keyword(s):  
Nonlinear Dynamics ◽  
Communication Network ◽  
Control Strategy ◽  
Control Law ◽  
Multi Agent System ◽  
Agent System ◽  
Action Function ◽  
Multi Agent ◽  
Theoretical Results ◽  
Event Triggered

In this paper, a distributed event-triggered control strategy is proposed to investigate aflocking problem in a multi-agent system with Lipschitz nonlinear dynamics, where triggeringconditions are proposed to determine the instants to update the controller. A distributedevent-triggered control law with bounded action function is proposed for free flocking. It is provedthat the designed event-triggered controller ensures a group of agents reach stable flocking motionwhile preserving connectivity of the communication network. Lastly, simulations are provided toverify the effectiveness of the theoretical results.

Decentralized polynomial trajectory generation for flight formation of quadrotors

2017 ◽  
Vol 231 (4) ◽  
pp. 690-707
Author(s):  
Hassan Sayyaadi ◽  
Ali Soltani
Keyword(s):  
Trajectory Tracking ◽  
Information Exchange ◽  
Formation Control ◽  
Optimization Problem ◽  
Translational Motion ◽  
Trajectory Generation ◽  
Control Law ◽  
Communication Topology ◽  
Tracking Controller ◽  
Trajectory Tracking Controller

This paper deals with the decentralized polynomial trajectory generation for the formation flight of a leader–follower network of quadrotors. The proposed decentralized trajectory planning method guarantees stability of the formation in missions with aggressive trajectories or low information exchange frequencies or data loss. Moreover, designed formation protocol ensures robustness of the formation against variations of the network communication topology. First, quadrotor translational dynamics is represented as a quadruple integrator by linearizing and differentiating its equations of translational motion. Then, a formation control law for a leader–follower network of the quadruple integrators is designed by implementing robustness properties of linear quadratic regulator design method and special characteristics of the network graph. Moreover, sufficient condition for the robustness of the formation against possible variations of the communication topology is addressed. According to the represented trajectory generation algorithm, once a follower receives information from its neighbors (e.g. coefficients of their intended polynomial trajectories), it plans a polynomial trajectory. To generate proper trajectories, integral of squared magnitude of error between the snap of the trajectory and its determined value by the formation control law over a finite horizon time should be minimized. The optimization problem can be formulated as a quadratic problem, which can be solved in real time. Furthermore, actuators limits can be imposed on the optimization problem as inequality constraints. As it is validated in the simulations, this predictive model of the trajectory generation provides stability of the formation in operations with aggressive trajectories or low information update frequencies or probability of data packets loss. Additionally, the quadrotors track the planned trajectories via implementing a hierarchical nonlinear trajectory tracking controller including a position controller and a geometrical attitude controller. Stability of the tracking error dynamics is proven by Lyapunov stability theorem. Expected capabilities of the formation control law, trajectory generation method and nonlinear trajectory tracking controller are examined in numerical simulations. In all of the simulations, an experimentally verified full model of a specific quadrotor taken from literatures is used.

Time-Varying Formation Control for Heterogeneous Planar Underactuated Multi-Vehicle Systems

2021 ◽  
Author(s):  
Bo Wang ◽  
Sergey Nersesov ◽  
Hashem Ashrafiuon
Keyword(s):  
Formation Control ◽  
Sliding Mode ◽  
Nonholonomic Constraints ◽  
Rigid Bodies ◽  
Control Law ◽  
Time Varying ◽  
Local Motion ◽  
Order Error ◽  
Control Approach ◽  
Vehicle Networks

Abstract This paper presents a distributed control approach for time-varying formation of heterogeneous planar underactuated vehicle networks without global position measurements. All vehicles in the network are modeled as generic three degree of freedom planar rigid bodies with two control inputs, and are allowed to have non-identical dynamics. Feasible trajectories are generated for each vehicle using the nonholonomic constraints of the vehicle dynamics. By exploiting the cascaded structure of the planar vehicle model, a transformation is introduced to define the reduced order error dynamics, and then, a sliding-mode control law is proposed. Low level controller for each vehicle is derived such that it only requires relative position and local motion information of its neighbors in a given directed communication network. The proposed formation control law guarantees the uniform global asymptotic stability (UGAS) of the closed-loop system subject to bounded uncertainties and disturbances. The proposed approach can be applied to underactuated vehicle networks consisting of mobile robots, surface vessels and planar aircraft. Simulations are presented to demonstrate the effectiveness of the proposed control scheme.

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